The effect of histidine on the structure and antitumor activity of metal-5-halouracil complexes

The ternary complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) ions with 5-halouracils, viz., 5-fluorouracil (5FU), 5-chlorouracil (5ClU), and 5-bromouracil (5BrU), and the biologically important ligand L-histidine (HISD) have been synthesized and characterized by elemental analysis, conductance measurements, infrared spectra, electronic spectra, and magnetic moment (room temperature) measurements. On the basis of these studies, the structures of the complexes have been proposed. All these ternary complexes were screened for their antitumor activity against Dalton's lymphoma in C3H/He mice. It was found that only Mn(II)-5BrU-HISD, Co(II)-5BrU-HISD, Cu(II)-5ClU-HISD, Cu(II)-5BrU-HISD, Zn(II)-5FU-HISD, and Zn(II)-5BrU-HISD complexes have significant antitumor activity with T/C greater than 125% (where T and C represent mean lifespan of treated mice and control mice respectively). The Mn(II)-5FU-HISD, Co(II)-5FU-HISD, Co(II)-5ClU-HISD, Ni(II)-5ClU-HISD, Ni(II)-5BrU-HISD, and Zn(II)-5ClU-HISD complexes are also effective antitumor agents, with T/C greater than 115%. The complexes that showed effective antitumor action in vivo were also found to inhibit 3H-thymidine incorporation (DNA replication) in Dalton's lymphoma cells in vitro.     

Transfer of Brassica tournefartii (TT) genes to allotetraploid oilseed Brassica species (B. juncea AABB, B. napus AACC, B. carinata BBCC): homoeologous pairing is more pronounced in the three-genome hybrids (TACC, TBAA, TCAA, TCBB) as compared to allodiploids (TA, TB, TC)

For the transfer of genes from B. tournefortii (TT) to the allotetraploid oilseed brassicas, B. juncea AABB, B. carinata BBCC and B. napus AACC, B. tournefortii was first crossed with the three basic diploid species, B. campestris (AA), B. nigra (BE) and B. oleracea (CC), to produce the allodiploids TA, TB and TC. These were tetraploidized by colchicine treatment to produce the allotetraploids TTAA, TTBB and TTCC, which were further crossed with B. juncea and B. napus to produce three-genome hybrids with substitution-type genomic configurations: TACC, TBAA and TCAA. These hybrids along with another hybrid TCBB produced earlier, the three allodiploids, their allotetraploids and the four diploid parent species were studied for their male meiotic behaviour. The diploid parent and the allotetraploids (TTAA, TTBB and TTCC) showed regular meiosis although the pollen viability was generally low in the allotetraploids. In the allodiploids (TA, TB and TC) only some end-to-end associations were observed without any clearly discernible chiasmata or exchange points. Chromosomes involved in end-to-end associations were randomly distributed at the metaphase/anaphase-I stages. In contrast, the three-genome hybrids (TACC, TBAA, TCAA and TCBB) showed normal bivalents whose number exceeded the expected bivalent values. Bivalents arising out of homoeologous pairing were indistinguishable from normal pairs by their disjunction pattern but could be distinguished on the basis of the heteromorphy of the homoeologous chromosomes. The three-genome hybrids could be backcrossed to allotetraploid oilseed brassicas as they had some fertility. In contrast, the allodiploids could neither be selfed nor back-crossed. On the basis of their meiotic stability, in terms of more pronounced homoeologous pairing and fertility for backcrossing, the three-genome configurations provide the best possible situation for the introgression of alien genes from the secondary gene pool to the allotetraploid oilseed crops B. juncea, B. napus and B. carinata.     

Somatic hybrids with substitution type genomic configuration TCBB for the transfer of nuclear and organelle genes from Brassica tournefortii TT to allotetraploid oilseed crop B. carinata BBCC

Oilseed crop Brassica carinata BBCC is a natural allotetraploid of diploid species B. nigra BB and B. oleracea CC. To transfer the nuclear and organelle genes in a concerted manner from an alien species, B. tournefortii TT, to B. carinata, we produced somatic hybrids with genomic configuration TCBB using B. nigra and B. oleracea stocks that carried selectable marker genes. B. tournefortii TT was sexually crossed with hygromycin-resistant B. oleracea CC. Protoplasts isolated from shoot cultures of hygromycin-resistant F₁ hybrids of B. tournefortiixB. oleracea TC were fused with protoplasts of kanamycin-resistant B. nigra BB. In two different fusion experiments 80 colonies were obtained through selection on media containing both hygromycin and kanamycin. Of these, 39 colonies regenerated into plants. Analysis of 15 regenerants by random amplified polymorphic DNA (RAPD) markers showed the presence of all three genomes, thereby confirming these to be true hybrids. Restriction fragment length polymorphism (RFLP) analysis of organelle genomes with heterologous chloroplast (cp)and mitochondrial (mt) DNA probes showed that the chloroplast genome was inherited from either of the two parents while mitochondrial genomes predominantly showed novel configurations due to either rearrangements or intergenomic recombinations. We anticipate that the TCBB genomic configuration will provide a more conducive situation for recombination between the T and C genomes during meiosis than the TTCCBB or TCCBB type configurations that are usually produced for alien gene transfer. The agronomic aim of producing TCBB hybrids is to transfer mitochondrial genes conferring cytoplasmic male sterility and nuclear genes for fertility restoration from B. tournefortii to B. carinata.     

IMPRINTING EFFECTS OF THREE AMINO ACIDS (ALANINE,LYSINE AND GLYCINE) AND THEIR OLIGOPEPTIDES INTETRAHYMENA PYRIFORMIS. DATA FROM THE HORMONE AND HORMONE RECEPTOR EVOLUTION

Hormonal imprinting takes place at the first encounter of the hormone and receptor, and results in a changed binding capacity and reaction of the cell and its progeny generations. The imprinting effect of three amino acids and their oligopeptides is studied using fluorescent-labelled peptides. Glycine and lysine could provoke positive imprinting (increased binding in the progeny generations) for their own peptides, but alanine could not. Mostly positive imprinting was provoked by glycine and lysine peptides for their own peptides of different chain length. The optimal chain length provoking self-imprinting was four for glycine, two for lysine and three for alanine. Except in this case, alanine was neutral or provoked mostly negative imprinting. After reaching the optimal chain length, there is a decline in binding. Evolutionary conclusions are discussed.     

Microbial biofilm ecology,in silico study of quorum sensing receptor-ligand interactions and biofilm mediated bioremediation

Archives of Microbiology - Biofilms are structured microbial communities of single or multiple populations in which microbial cells adhere to a surface and get embedded in extracellular polymeric...     

Microsatellite Analysis of Genetic Population Structure of Zebu Cattle (Bos indicus) Breeds from North-Western Region of India

The present study aims to understand the existing genetic diversity and structure of six native cattle breeds (Rathi, Tharparkar, Nagori, Mewati, Gir, and Kankrej) adapted to the north-western arid and semi-arid region of India based on microsatellite loci. Various diversity estimates, mean number of alleles (12.84); effective number of alleles (5.02); gene diversity (0.769), and observed heterozygosity (0.667) reflected the existence of substantial within-breed diversity in all the investigated cattle breeds. Mean estimates of F-statistics: F_IT = 0.144 ± 0.023, F_IS = 0.071 ± 0.021, and F_ST = 0.078 ± 0.014 were significantly different from zero (P < 0.05). The interbreed relationships indicated moderate level of breed differentiation between the six cattle breeds with least differentiation between Kankrej-Mewati pair. The phylogeny structuring further supported close grouping of Kankrej and Mewati breeds. Correspondence analysis plotted Rathi, Tharparkar, and Gir individuals into three separate areas of multivariate space; whereas, Kankrej, Mewati, and Nagori cattle showed low breed specific clustering. This reflected the existence of discrete genetic structure for Tharparkar, Rathi, and Gir, the prominent dairy breeds of the region; whereas, admixture was observed for Kankrej, Mewati, and Nagori individuals.     

Intense photon emission induced by fracture of γ–irradiated Dy‐, Tm‐, Sm‐ and Mn‐doped CaSO4 single crystals

When an γ‐irradiated Dy‐, Tm‐, Sm‐ or Mn‐doped CaSO₄ crystal is impulsively deformed, two peaks appear in the ML intensity versus time curve, whereby the first ML peak is found in the deformation region and the second in the post‐deformation region of the crystals. In this study, intensities I_m1 and I_m2 corresponding to first and second ML peaks, respectively, increased linearly with an impact velocity v₀ of the piston used to deform the crystals, and times t_m1 and t_m2 corresponding to the first and second ML peaks, respectively, decreased with impact velocity. Total ML intensity initially increased with impact velocity and then reached a saturation value for higher values of impact velocity. ML intensity increased with increasing γ‐doses and size of crystals. Results showed that the electric field produced as a result of charging of newly‐created surfaces caused tunneling of electrons to the valence band of the hole‐trapping centres. The free holes generated moved in the valence band and their subsequent recombination with electron trapping centres released energy, thereby resulting in excitation of luminescent centres. Copyright © 2012 John Wiley & Sons, Ltd.     

Cell Budding from Normal Appearing Epithelia: A Predictor of Colorectal Cancer Metastasis?

Background: Colorectal carcinogenesis is believed to be a multi-stage process that originates with a localized adenoma, which linearly progresses to an intra-mucosal carcinoma, to an invasive lesion, and finally to metastatic cancer. This progression model is supported by tissue culture and animal model studies, but it is difficult to reconcile with several well-established observations, principally among these are that up to 25% of early stage (Stage I/II), node-negative colorectal cancer (CRC) develop distant metastasis, and that circulating CRC cells are undetectable in peripheral blood samples of up to 50% of patients with confirmed metastasis, but more than 30% of patients with no detectable metastasis exhibit such cells. The mechanism responsible for this diverse behavior is unknown, and there are no effective means to identify patients with pending, or who are at high risk for, developing metastatic CRC.Novel findings: Our previous studies of human breast and prostate cancer have shown that cancer invasion arises from the convergence of a tissue injury, the innate immune response to that injury, and the presence of tumor stem cells within tumor capsules at the site of the injury. Focal degeneration of a capsule due to age or disease attracts lymphocyte infiltration that degrades the degenerating capsules resulting in the formation of a focal disruption in the capsule, which selectively favors proliferating or “budding” of the underlying tumor stem cells. Our recent studies suggest that lymphocyte infiltration also triggers metastasis by disrupting the intercellular junctions and surface adhesion molecules within the proliferating cell buds causing their dissociation. Then, lymphocytes and tumor cells are conjoined through membrane fusion to form tumor-lymphocyte chimeras (TLCs) that allows the tumor stem cell to avail itself of the lymphocyte''s natural ability to migrate and breach cell barriers in order to intravasate and to travel to distant organs. Our most recent studies of human CRC have detected nearly identical focal capsule disruptions, lymphocyte infiltration, budding cells, and the formation of TLCs. Our studies have further shown that age- and type-matched node-positive and -negative CRC have a significantly different morphological and immunohistochemical profile and that the majority of lymphatic ducts with disseminated cells are located within the mucosa adjacent to morphologically normal appearing epithelial structures that express a stem cell-related marker.New hypothesis: Based on these findings and the growth patterns of budding cells revealed by double immunohistochemistry, we further hypothesize that metastatic spread is an early event of carcinogenesis and that budding cells overlying focal capsule disruptions represent invasion- and metastasis-initiating cells that follow one of four pathways to progress: (1) to undergo extensive in situ proliferation leading to the formation of tumor nests that subsequently invade the submucosa, (2) to migrate with associated lymphocytes functioning as “seeds” to grow in new sites, (3) to migrate and intravasate into pre-existing vascular structures by forming TLCs, or (4) to intravasate into vascular structures that are generated by the budding cells themselves. We also propose that only node-positive cases harbor stem cells with the potential for multi-lineage differentiation and unique surface markers that permit intravasation.     

Differentiation dynamics of mammary epithelial stem cells from Korean holstein dairy cattle under ECM-free conditions

The “stem cells” are commonly defined as “cells capable of self-renewal through replication and differentiating into specific lineages”. The mammary gland contains functional stem/progenitor cells. The current study was planned with the objectives to study the differentiation dynamics of Korean Holstein mammary epithelial stem cells (KHMESCs) under the optimum culture conditions. Lineage negative KHMESCs isolated from mammary tissue of lactating cows have shown the typical differentiation dynamics with formation of lobulo–alveolar structures in in vitro culture. This suggests the existence of bipotential mammary epithelial stem cells in the mammary gland. The strong mRNA expression of pluripotency factors indicates stemness, whereas expression of milk protein genes and epithelial cell-specific gene indicate their differentiation capabilities. Further, immunostaining results have shown the differentiation capabilities of KHMESCs into both luminal and basal lineages under the extracellular matrix (ECM, matrigel) free environment. However, under matrigel, the differentiation process was comparatively higher than without matrigel. Immunostaining results also suggested that differentiated cells could secrete milk proteins such as β-casein. To our knowledge, these data represent the first report on the differentiation dynamics and establishment of mammary epithelial stem cells from Korean Holstein with typical stemness properties. It was observed that isolated KHMESCs had normal morphology, growth pattern, differentiation ability, cytogenetic and secretory activity even without ECM. Therefore, it is concluded that established KHMESCs could be used for further studies on Korean Holstein dairy cows related to lactation studies, as non-GMO animal bioreactors and stem cell-based management of bovine mastitis including post-mastitis damage.